Broadly, the invention relates to providing a vapor phase sample for analysis. More specifically, the invention is directed to providing a vapor phase sample for analysis, in which the sample, at ambient temperature and pressure, contains a mixture of condensable and non-condensable components.
In some chemical processes the composition of the product, at ambient temperature and pressure, is a mixture of a non-condensable gas phase, an aqueous phase, and an organic liquid phase. An example of such a product is a mixture which contains, water, hydrogen, oxides of carbon, aromatic hydrocarbons, and aliphatic hydrocarbons. It is very difficult to achieve reliable on-line sampling of such a mixture, particularly if the aromatic hydrocarbons are polymerizable materials. For example, in certain types of sampling systems the polymer materials will build up in the sampling line and plug it off entirely.
There are several other problems in the on-line sampling of such a composition. For example, in one of the prior sampling techniques the sample mixture described above is collected from the chemical process and thereafter cooled. The cooling step condenses the water, the aromatic hydrocarbons, and some of the aliphatic hydrocarbons. The water and the organic liquid phases are then analyzed separately. However, it is extremely difficult to analyze the non-condensable gas phase, because some of the water and the hydrocarbons become entrained in the non-condensable gas phase.
The present invention eliminates the problems described above in that it provides a system in which the entire sample mixture is delivered to an on-line analyzer as a vapor phase sample.